


Willpower (and Lots of It)

by FierySprites



Category: Fate/stay night & Related Fandoms, Fate/stay night (Visual Novel), Kingdom Hearts (Video Games)
Genre: Archer is Screaming, Crack, Crack Treated Seriously, Crossover, Fantasy, Fate/Stay Night spoilers, Gen, One-Shot, Saber is Screaming, Sora is Confused, Spoilers, Terra is Very Angry™, The Masters are Screaming, everyone is screaming, yay bonus bosses
Language: English
Status: Completed
Published: 2021-01-29
Updated: 2021-01-29
Packaged: 2021-03-15 22:48:40
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,519
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29072064
Author URL: https://archiveofourown.org/users/FierySprites/pseuds/FierySprites
Summary: The Servants of the Fifth Holy Grail War are summoned into the Keyblade Graveyard.The Lingering Will dislikes this intrusion.(A crack crossover betweenFate/stay nightandKingdom Hearts.)
Comments: 2
Kudos: 20





	Willpower (and Lots of It)

**Author's Note:**

> For the Nasuverse, the cast are pulled from an unspecified point early in _Fate/stay night’s_ plot, with no emphasis on any of the three routes. Various spoilers from all three routes are alluded to, with Rider and her Master being the most apparent.
> 
> For the _Kingdom Hearts_ universe, this one-shot is set sometime either during or after the events of _Kingdom Hearts II_ (whichever one’s the case is up to you). No spoilers for said game—or any entry in the Dark Seeker Saga—are featured.

**Keyblade Graveyard  
Badlands**

It all happened in an instant.

One moment, Rin and Archer were relaxing at the Tohsaka Mansion, enjoying the rare night of peace and quiet together—

—the next, they had been unceremoniously plopped into some dusty old graveyard, barely able to steel themselves before the fall.

_“Waaaaaaaaaaaaaaaa—! **Oomph!”**_

The teenage Magus fell flat on her ass, head throbbing in disorientation.

_“Ohhhhhhhhhh… what happened…?”_

Archer dusted himself off and looked around at their surroundings.

He frowned.

“We appear to have been whisked away from Fuyuki into a…” He paused. “…I’m not sure how to describe it, but ‘empty desert’ is the first thing that comes to mind.”

_~~It’s like **Unlimited Blade Works** … but even more lifeless, somehow.~~ _

_~~How grueling…~~ _

Rin stood up, annoyance creeping into her voice. “Well, that’s just great! This must be the doing of some upstart Servant, trying to get at us while we’re vulnerable! I’ll show them to mess with me…!” She cupped her hands around her mouth and shouted, _“Hey! What’s going on here!? Come out and face me!”_

Silence.

And then, a blue-and-black vortex appeared in the air.

Several of them, in fact.

Rin took a step back. “Wh-What the heck…!?”

Archer tensed. “A counterattack…!?” he muttered.

_Don’t tell me—this is **his** doing—!?_

Thankfully, his fears were unfounded. Instead, the portal closest to them only expelled Shirou and Saber instead.

“Oof!” Shirou groaned, face eating the earth. “That was… unpleasant…”

Saber, in particular, seemed vexed by this interruption. “And right as I was about to eat dessert, too…! Who is the fiend that would disrupt our dinner so!? I will have their heads for this!”

Rin stared. “Emiya-kun? Saber? Did—Did you get caught in this trap, too?”

“Tohsaka?” The wannabe Hero of Justice got back onto his feet, supported by his Servant. “I wouldn’t know about any trap, but… it _does_ look like we’ve been stolen from our homes.” He looked quizzical. “Is this some sort of test, or something? Are we supposed to work together to escape?”

(“I hope not,” Archer muttered.)

“It matters not the purpose for why we were brought here,” Saber solemnly stated—“simply that we return to our prior excursions as fast as possible. I have yet to finish my meal, and by the Grail, I refuse to rest until I— _Shirou, get back!_ ”

Abruptly, the swordswoman summoned her armor and invisible blade, leaping to her Master’s defense at the sight occurring above her.

Archer narrowed his eyes and traced his trademark married blades.

The wormholes were dropping a whole cast of people: Lancer, Rider, Caster, Assassin, Berserker—

All of the Masters and all of the Servants of the Fifth Holy Grail War ~~(save two… or three… or four)~~ were being forcefully gathered in this arid wasteland of a world, much to the astonishment of the four already there.

“You gotta be kidding me…!” Rin said. “Is this—Is this happening all over Fuyuki…!?”

“No way…” Shirou gulped. “This isn’t good…! I think we’re in for one heck of a fight!”

 _For once, you said it,_ Archer thought.

The red-clad guardian was… semi-confident in his ability to out-maneuver most of the other Servants one-on-one.

All of them at once, though?

Yeah, that wouldn’t be any contest.

Lancer was the first to get up. He looked at his surroundings, eventually commenting, “…this isn’t the Land of Shadows. Way too brown for that…”

He turned around and waved at Team Emiya. “Yo! Saber, Archer! How’ve you all been?”

“Lancer,” Saber greeted, cautiously. “We’ve been… better.”

Behind them, everyone else was similarly recovering from their impromptu dynamic entry.

“Why, Uncle Kariya…?” Sakura squirmed, still half-asleep. “Why didn’t you…?”

Rider frowned, shifting her stance as she carried her Master.

“Awawawawawa…” Illya’s eyes spun. “Sella…? Leysritt…? Did you get me that new _Sonic_ game yet…?”

 ** _“Grrrrrrrrrrrr…”_** Berserker rumbled.

“Souichirou-sama…” Caster murmured. “Please don’t leave me…”

“Is this… what freedom feels like…?” Assassin wondered. “My, how dusty…”

Eventually, they had all come back to their senses…

…and then they realized exactly where they were.

 ** _“YOU!”_** dropped from several mouths.

“How dare you!” Caster screeched, having immediately decided to pin Team Emiya as the villains (for some reason). “Interrupting my precious time with my Master…! Have you no shame!?”

“Onii-chan? Is that you?” Illya tilted her head. “Well, this isn’t how I’d thought we’d meet up again, but this is fine by me! How do you want to die today: turned into paste, or broken like a Kit Kat?”

“We’re not the ones behind this, Caster!” Shirou insisted. “And Illya, no one needs to die! I don’t know what your beef is, but please, we don’t have to fight!”

“Hmm… nah! Still wanna kill you!”

“Lancer… Caster… Assassin… Berserker… and Rider, too!?” Rin counted off, appearing increasingly more panicked. “And—wait, is that _Sakura!?”_

_No… it can’t be…_

_She—She **can’t** be involved in this—_

The younger Matou’s eyes blinked awake, and she stared at Rin in a strange mixture of apprehension and—something else. “T-Tohsaka-senpai…?”

“So… y-you’re her real Master, huh?” Rin said, looked away. “I should have expected this…”

Sakura dropped her head. “…it’s not what you think…”

“I dunno what’s going on, but if it involves us getting into a good fight, then I’m perfectly fine with that,” Assassin chimed in.

 _“Now_ you’re speaking my language,” Lancer grinned. “I wonder what kind of foe we’ve been brought here to face. Hope it’s a good one!”

“Lancer! Assassin! Now is not the time!” Saber scolded them. “We should focus on trying to get trying to get out of here, not trying to pick a fight with whoever we can find!”

The spearman laughed. “Oh, come on, Saber,” he said, “what’s so bad about that? I’ve barely gotten to fight anything; what’s the worst that could happen?”

It was then that Archer’s nerves abruptly went into overdrive.

“Rin! Something’s happening!”

She jolted. “Wha—!?”

The wind started to pick up, creating a whirlwind of dust in front of the eleven present Grail War participants. It twisted and coiled, forcing to cover their eyes from the intensity—

—and then it was gone, leaving in its epicenter a kneeling suit of armor, resting on a blade that looked oddly like… a key?

Archer’s head hurt just looking at it. ~~(Shirou’s, too.)~~

_What the—What **is** that thing?_

Confusion ensued.

“Wh-Who is that…?” Sakura squeaked.

“My my,” Assassin hummed—“this is… unexpected.”

Several of them were sporting eyes wide as oranges. They could sense a spirit in that armor—an unknown entity. Not unlike a Servant… but not exactly one, either.

“Eh!? This is what we were dragged here for?” Illya pouted. “Some weird statue?”

_“Aqua… Ven…”_

Saber reeled. _“It speaks!”_

The Servants summoned their weapons, carefully eyeing the mysterious entity.

_“This feeling… you’re magic. All of you.”_

“Hmph. We’re not _just_ ‘magic’,” Caster corrected—“we are the Servants of the Holy Grail War, heroes and legends from ages long past. What may _you_ be? A golem? A homunculus, perhaps?”

_“…what is this… Holy Grail War? Is it… like the **Keyblade War**?”_

There was a noticeable tensing in the figure’s voice.

“Keyblade War?” Rin had never heard that term before. “No, it’s not like… whatever that is! It’s a ritual between seven mages and seven Servants, wherein we compete to reach Akasha, the Root of All—”

“Pfft!” Illya scoffed. “That’s not what it’s about! It’s a big tournament where we murder each other, and then we get a cool wish at the end. Nobody really _cares_ about reaching the Root!”

Shirou and Saber sweatdropped.

_“Murder…? Root…? Wish…? You all… You’re no better than **him,** are you?”_

“Hey, it’s not like that!” Shirou protested. “Not all of us are out for each other’s blood! I’m trying to prevent casualties, and Tohsaka is—”

_“Xe… ha… nort… Are these… your lackeys…?”_

Everyone paused.

 _…Xehanort?_ Archer blinked. _What’s a Xehanort?_

“I assure you, whatever you’re thinking of, it’s not like that,” Saber said, clipping her lip. “We have just been displaced, and we are simply seeking a way home—”

_“Xeha… nort…”_

An aura of pure, unadulterated _rage_ began to be emanated from the possessed shell. It was so strong and so palpable, no one—Servant or otherwise—could resist taking a few steps back in fear.

Even Berserker was a bit dumbfounded by the sheer amount of it the guy was emitting—and he was practically known for it.

**_“Grr?”_ **

“Guys?” Lancer called, eyes wide. “Are you getting the feeling we should be running away right about now?”

The atmosphere became almost suffocating. The armored figure shook and shook, memories of the past screaming in his mind. He went on like this, submerging himself in his fury, until finally…

…he could bear it no longer.

[ **_“XEHANORT!”_ ** ](https://www.youtube.com/watch?v=edRn2fdDBZM)

He lifted his knees and stood up, pulling his Keyblade out of the ground.

Illya shook her head in an attempt to put her fear aside.

“H-Ha!” she cried, voice wobbly. “We—We can take you on in a heartbeat, you piece of junk! Berserker! Get him!”

The mighty titan roared and leaped toward the standing entity—

—who promptly proceeded to assemble a dozen stream of chains, wrapping around the celebrated Hero of Greece.

 **_“…brr.”_ ** _~~(Translation: ‘Oh, crap.’)~~_

_BAM! BAM! BAM! BAM! BAM! BAM! **BAM!**_

Berserker was slammed into the floor repeatedly and then thrown into a tall rock a dozen yards away from the badlands.

Illya froze in confusion. “Eh?”

The other nine otherworlders stared blankly as well, unable to process the utterly lopsided contest of Madness Enchantment.

And then the spirit turned his blade into a giant cannon, aiming it directly at them.

_…crap._

**_“SCATTER!”_** Archer shouted.

Everyone did so.

A humongous explosion erupted right where they used to be.

It was at that moment that they knew:

They were screwed, and thoroughly so.

* * *

A few minutes later…

* * *

Sora was confused.

Like, really, _really_ confused.

He, Donald, and Goofy had been summoned to Disney Castle in order to investigate this strange wormhole in the Hall of the Cornerstone. Chip and Dale made it sound pretty dire, and it wasn’t like they could let His Majesty’s kingdom get devastated by… whatever this latest threat was!

So they had packed up their supply of Elixirs, equipped their strongest batch of weapons and gear, and set off to save the world!

…again.

And potentially stop the Cornerstone from being abused!

…again.

They had arrived in decent time, and charged into the glorified Warp Hole without another second’s thought.

On the other side of it, though…

…

Well, Sora could safely say he hadn’t seen _this_ before.

Seven warriors were desperately struggling against this guy in armor, the latter wielding some kind of Keyblade. ~~(That could _transform? **Seriously?)**_~~

Three of them were physically engaging the Keybearer in question: a blonde-haired knight, a blue-clad spearman, and a brown muscle-maniac. The first fought with style and grace; the second with a frightening level of ferocity. The third reminded Sora of that one Absent Silhouette he had fought—and that Keybearer…

…‘angry’ didn’t even _begin_ to describe him.

“You are a persistent foe,” the knight muttered, her teeth tightly ground. “Normally noble, but currently infuriating!”

“Man, to think that we can triple-team you and you can _still_ fight unimpeded,” the spearman commented, a bead of sweat going down his face. “You’re really something else, you know that!?”

**_“ROOOOOOOOOOOOOOOOAAAAAR!”_ **

The titan didn’t even bother with words.

He just kept trying to smash the specter with everything he had.

Meanwhile, there were a bunch of these drones flying around, at least a dozen, firing beams of plasma at just about everyone and everything. There was this red-shrouded bowman firing these swords at them, another samurai slashing about and keeping the heat out of him, and there was a blindfolded woman flying on a _pegasus ~~(that wasn’t stolen from Herc, was it?)~~_ dealing with whatever was left.

“Tch…!” the bowman hissed. “There are more of these than I expected. This man just doesn’t know when to give up!”

“Sadly, this isn’t quite the fight I wanted to be in,” Assassin said, parrying several shots wth his katana. “I hope the end of this isn’t too far behind us…”

Also of note were the blue diamond orbs hovering over the Lingering Will, and the equally-as-blue glyph sitting above this hooded witch’s head.

She was grumpily leaning on a spire away from the fight, arms crossed and lips pouting petulantly.

 _“Stupid speed… stupid slam…”_ she grumbled. _“Why can’t I deal with normal people instead of this…?”_

“Donald? Goofy?” Sora blinked. “What’s going on?”

“I don’t know!” Donald squawked. “I don’t recognize any of these weirdos!”

“Whoa,” a little girl’s voice interrupted them.

The trio turned toward the source of the exclamation—and came face-to-face with a group of four kids with varying hair colors: one orange, one black (and twin-tailed), one violet (and tied up in a ribbon) and one white (and kept really long).

“Can it be true?” the last of them said, eyes wide. “Are you actually _Disney_ characters?”

Goofy hummed. “We’re from the Magic Kingdom, if that’s what you’re talkin’ ‘bout.”

“You have got to be kidding me,” the orange-haired boy said. “First Heroic Spirits, now **_Disney?”_**

“Do I know you?” the duck deadpanned.

“I have no idea what you two are talking about,” the dark-haired girl stated. “What is a Disney and how does it relate to these three?”

“Umm…” The violet one bit her lip. “It’s—It’s a good thing you came. We got sucked into this place, and we need some help getting out. That man over there… he won’t listen to anything we say.”

“He’s really strong, too,” the not-quite-redhead remarked. “If you’ve got something that can stop him, we’d gladly appreciate it.”

In the background, the Lingering Will broke out of the lopsided stalemate and turned his Keyblade into a whip, forcing everyone back as it had a rather ridiculous range. The titan attempted to tank it and rush right in—and then he was besieged by a deadly multi-hit combo, petals of darkness fluttering behind him.

And then he raised his Keyblade and summoned a giant meteor to fall onto the battlefield.

Sora winced at the sounds of panic going around.

“Yeah, it definitely sounds like we should lend a hand,” the fifteen-year-old stated. “Donald, Goofy, you ready?

“Of course, ayuck!” Goofy affirmed.

“This better not be like Sephiroth…” Donald grumbled.

The three ~~Junior~~ Heroes charged forward, Ultima Weapon and Save the King+ and Save the Queen+ in hand.

“He has one of those key things too?” Shirou gawked.

“Oh come on, why do _they_ get all the cool Mystic Codes!?” Rin complained. “Or Noble Phantasms, or whatever!”

The Lingering Will also noticed this.

_“What? A Keyblade…?_

_“It feels like **him** —the one I chose—but it **isn’t.**_

_“What is this…!? **XEHANOOOOOOORT!”**_

The animate armor promptly whipped out the Ultima Cannon again, and things simply kept escalating from there.

_“Eeegh—!”_

_“WAAAAAAGH—!”_

_“Somebody come quick!”_

…

…

…

…

…

“Hey, do you think I’ll be able to contract the armored spirit as a second Berserker?” Illya innocently asked.

Shirou and Rin instinctively shuddered.

“…m-maybe you shouldn’t,” Sakura diplomatically answered.

**Author's Note:**

> I think we’ve met one of the few people who can out-Berserker Berserker.
> 
> The Lingering Will is somewhat infamous for being one of the hardest Bonus Bosses in _Kingdom Hearts_ history. He has been surpassed since (unfairly in _Birth by Sleep’s_ case; fairly in case), but his legacy will never be forgotten.
> 
> Thus, I thought it’d be a funny idea to pit the Servants of _Fate/stay night_ —themselves fairly accomplished and strong legends—against the might of Terra’s unrelenting rage.
> 
> Is this dumb? Yes.
> 
> But dang if it wasn’t a hoot to write.
> 
> I’d do the whole fight, but I don’t have infinite time on my hands—so, this small snippet is all I can do. Ah well; at least I finally got this out of my system.
> 
> …also, happy 2nd anniversary, _Kingdom Hearts III._ Praise be to the end of Xehanort.
> 
> Well, that’s all for now – see you around!


End file.
